Purpose of Study (Succinct summary of what is to be learned): The proposed study will examine parameters of sympathetic nervous system activity in depressed patients prior to and after completing ECT. The hypotheses to be examined are: 1)Depressed patients will have increased norepineptuine and cardiovascular reactivity and decreased HR variability to a lab speech stressor, to anticipation of ECT, and to daily events during Molter monitoring. This will normalize in many but not all patients after successfull ECT. 2) Subjects who have noramlization of indexes of sympathetic nervous system tone will be less likely to have a relapse within six months.